1. Field of the Invention
This invention relates generally to an apparatus, such as, an optical disc player, in which a light beam is directed against a disc or other record medium surface for optically reading information recorded in a track on such surface, and more particularly is directed to an improved objective lens assembly for such apparatus.
2. Description of the Prior Art
It is known, for example, as disclosed in U.S. Pat. No. 4,135,083, to provide an optical disc player with a focusing servo by which the light beam from a laser light source is correctly focused on the disc surface through an objective lens, and also with a tracking servo by which the point of impingement of the focused light beam on the disc surface is made to coincide with the track being scanned or read. Further, in the above identified U.S. patent, and particularly in FIGS. 7-10 thereof, and also in U.K. Patent Application GB No. 2,025,110A, it is disclosed to support the objective lens by first and second sets of springs which respectively permit the objective lens to be moved, in response to electromagnetically applied forces, both in the axial direction for correcting focusing errors, and in a direction extending radially in respect to the track being scanned for correcting tracking errors. However, the use of a plurality of leaf springs to support the objective lens, as aforesaid, leads to undesirable complexities in assembling the objective lens and its mounting structure, and gives rise to additional problems in that resonance is easily generated and, when the leaf springs are formed of metal, the value of Q becomes high and noises are likely to be produced during servo operation.